SCIN 131 Week 4 Exam Quiz 2023 (Questions with Correct Solutions) Graded

SCIN 131 Week 4 Exam Quiz 2023 (Questions with Correct Solutions) Graded. A sample of pure lithium carbonate contains 18.8% lithium by mass. What is the % lithium by mass in a sample of pure lithium carbonate that has twice the mass of the first sample? • A. 75.2% • B. 37.6% • C. 18.8% • D. 9.40% Feedback:Great! Mass percent discussed in Chapter 6.2. Question 11 of 25 4.0/ 4.0 Points `One of the first chemical WMDs, researchers initially produced VX nerve agent for retail sale in the 1950s as a pesticide. Thankfully, your likelihood of coming in contact with VX is extremely low - the world's stockpiles have been destroyed, including the United States' main stockpile in Anniston, AL. The molecular formula for this nerve agent is C11H26NO2PS, and it has a molar mass of 267.37 g/mol. Given this information, what is its empirical formula? • A. CH2.36N0.09O0.18P0.09S0.09 • B. C11H26NO2PS • C. C22H52N2O4P2S2 • D. C66H156N6O12P6S6 • E. none of these are the correct empirical formula Feedback:Great! Empirical Formula discussed in Chapter 6.2. Question 12 of 25 4.0/ 4.0 Points The empirical formula of an insecticide is found to be CHCl, and its molar mass is 290.8 g/mol. How many atoms of carbon are found in a molecule of the insecticide? • A. 6 • B. 4 • C. 3 • D. 2 • E. 8 Feedback:Great! Empirical Formula discussed in Chapter 6.2. Question 13 of 25 0.0/ 4.0 Points A vitamin contains the elements C, H, and O. It is known to contain 40.9% C and 4.58% H by mass. The molar mass of the vitamin has been found to be about 180 g/mol. The molecular formula for the vitamin is: • A. C4H6O4 • B. C6H8O6 • C. C14H18 • D. C2H3O2 • E. C3H4O3 Feedback:Empirical Formula discussed in Chapter 6.2. Part 2 of 3 - Part 02 28.0/ 40.0 Points Question 14 of 25 0.0/ 4.0 Points `Caves form mostly from the reaction of weak carbonic acid (which forms due to carbon dioxide that is in the water) with exposed limestone. What numbers go in the blanks below, in order from left to right, to balance this chemical equation? ___H2CO3(aq) + ___CaCO3(s) -- ___Ca(HCO3)2(aq) + ___CO2(g) + ___H2O(l)